inclined nuclear gas disk / composite systems / nested gas disks / power-law relationship / low-luminosity systems / flattened triaxial systems / power law / late-type systems / gas surface density / exponential law / Molecular gas / atomic gas / extended gas disks / dense gas / /
Chapter 5 Properties of Disk Galaxies Disk galaxies are typically composite systems, built from several stellar populations. Besides a thin, rotating disk, such galaxies often include thicker disks or spheroids.